| T1 |
|
(inlet hot fluid temperature, deg F) |
| t1 |
|
(inlet cold fluid temperature, deg F) |
| U |
|
(overall heat-transfer coefficient, BTU per hr per ft2 per deg F) |
| L |
|
(tube length, ft) |
| do |
|
(tube outside diameter, in) |
| n |
|
(number of tubes |
| c |
|
(specific heat of cold fluid, BTU per lb per deg F) |
| w |
|
(flow rate of cold fluid, lb per hr) |
| W |
|
(flow rate of hot fluid, lb per hr) |
| C |
|
(specific heat of hot fluid, BTU per lb per deg F) |
| P |
|
(temperature effciency, (t2-t1)/(T1-t1)) |